Don't read past end if last cookie is invalid.
Don't read past end if last cookie is invalid.

If there was no equal sign in the last cookie in the string, we would
read past the end looking for the next cookie.

varnish/libvmod-cookie,varnish/libvmod-cookie,lkarsten/libvmod-cookie,wjordan/libvmod-cookie,wjordan/libvmod-cookie,lkarsten/libvmod-cookie